Dimensional Stability of Grout-Type Materials Used as Connections for Prefabricated Bridge Elements

The research presented in this report focuses on addressing performance concerns related to dimensional stability (primarily early age shrinkage) of 11 commercially available grout-type materials. Some of these grouts, especially those classified as “non-shrink grouts,” have been observed to display significant dimensional instability when deployed in connection details during bridge construction projects. The test methods used to evaluate dimensional stability are those described in the ASTM C1107 test method. After an initial evaluation, it was observed that the test methods used for evaluating dimensional stability described in this standard specification consider several parameters simultaneously (e.g., chemical expansion and shrinkage, autogenous and plastic shrinkage, etc.), thus providing a qualitative approach that is only useful for comparative purposes. To more completely assess this variety of parameters, volume changes were assessed from a fundamental point of view, measuring pure expansion/shrinkage deformations via test methods such as ASTM C157 and ASTM C1698. The results show that most of the grouts evaluated in this research seemed to perform well in terms of dimensional stability when tested in accordance with ASTM C1107. However, separate testing to specifically assess autogenous and drying deformations (shrinkage and expansion) demonstrated that ASTM C1107 is not necessarily an appropriate means to capture the full range of critical dimensional stability behaviors. Given the fact that most of the cement-based grouts commonly exhibit shrinkage, this research also included additional tests focused on the partial shrinkage mitigation by including internal curing through the use of prewetted lightweight aggregates. In summary, this research demonstrates the types of shrinkage performance that can be expected from these types of grouts, the shortcomings of the commonly used test methods, alternative test methods that may better demonstrate real world performance, and an innovative way of reducing part of the shrinkage observed in some of the grouts.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 74p

Subject/Index Terms

Filing Info

  • Accession Number: 01599320
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-HRT-16-008
  • Contract Numbers: DTFH61-13-D-00007
  • Files: TRIS, ATRI, USDOT
  • Created Date: May 12 2016 2:21PM